This invention relates to apparatus for manufacturing, starting from metal plate strip cut lengths, ring members intended to be successively worked to form rims for vehicle wheels.
Usually, the welded plate wheels for vehicles are manufactured by connecting, for each wheel, a cup made of stamped plate to a rim obtained by working a ring member which, on its turn, is formed by welding to one another the end edge portions of a bent cut length of metal plate strip. For the production of these ring members equipments are used which comprise a series of stations, among which are mainly a cylinder bending machine (so-called calender), a flash welding machine and a machine for the mechanical removal of the excess material pushed out from the welding zone. These different machines are mounted, for forming a machining line, by simply connecting them sequentially to one another with the interposition of conveyer means for conveying the workpieces, and they work in a synchronized but substantially individual manner, the workpieces being simply taken from a machine which has completed its working cycle, and conveyed to the following machine for carrying out the subsequent working step. Such equipment has considerable overall dimensions, considerable transfer idle times, synchronization difficulties and, in connection with the different working times of the different stations, the incapability of fully exploiting the working capacity of certain stations, thus giving rise to a restriction of the productivity and to high manufacturing costs. Particularly, the welding station has much higher working times than those of the other stations, and therefore it gives rise to a serious restriction of the operative flow. Moreover, such equipment is not suitable for conveniently carrying out the welding by processes other than the flash welding process.